Growing from start to harvest takes dedication and education. So no, it isn't worth continuing unless you are willing to invest some into it. So:

1: Cant tell yet
2: See above
3: Judging from the last picture and the curled leaf in the background, no
4: Generally around 12 weeks from start to finish, 8 of those weeks spent in flower. Flowering is induced by changing the light cycle (photoperiod).